Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
220 Cards in this Set
- Front
- Back
retrograde orbit moon. axis of rotation = 157 degrees with respect to its planet's axis. Hence, one side always faces the planet
|
triton
|
|
7th largest moon & 16th largest object in the solar system. Larger than Pluto and and Eris.
|
triton
|
|
Its plains are dotted with pits, such as the Leviathan Patera, probably vents from which lava emerged. There are four flat plains, they are dotted with black points, maculae.
|
triton
|
|
contains a large series of fissures and depressions, known as "cantoloupe's terrain." the theory for its formation is diapirism, the rising of lumps of less dense materiel through a stratum of denser material, couuld also be cryovolcanism.
|
triton
|
|
Phoebe and Triton were thought to have originated from this region.
|
kuiper belt
|
|
first evidence for it was found in 1992. the first astronomer to suggeest its existence was frederick c. leonard.
|
kuiper belt
|
|
kenneth edgeworth hypothesized that the material within the primordial solar nebla was too widely spaced to turn into planets, so it turned into a bunch fo random objects.
|
kuiper
|
|
stretches from 30 AU to 55 Au. the classical part extends from 42-48, which comprises 2/3 of th ematerial. They are referred to as cubewanos.
|
kuiper belt
|
|
it has a cliff - berstein and trilling found evidence that its rapid decline in objects of 10 km or more is real. Explanations include that the material is too scarce at that distance to form large objects.
|
kuiper belt
|
|
studies indicate that it is composed of light hydrocarbon, ammonia and water ice, in common with comets. Roughtly the upper limit of the mass is estimated to be 1/10 of the mass of earth.
|
kuiper belt.
|
|
Neptune's influence is to weak to explain how the objects don't accrete and such massive vacuuming, though the Nice model proposes that it could have been the cause of mass removal of the past.
|
kuiper belt
|
|
It includes objects such as centaurs. Of the four largest TNO's, three (Eris, Pluto, Haumea) possess satellites. There are a lot of binaries.
|
Kuiper Belt
|
|
First spacecraft to explore it was New Horizons, headed by Alan Stern of Southwest Research Institute.
|
kuiper belt
|
|
he discovered two natural satellites in the solar system, namely Uranus's Miranda and Neptune's Nereid. He discovered carbon dioxide in Mars.
|
kuiper
|
|
spent most of his time at the University of Chicago, and he helped identify landing sites on the moon. He was awarded the Janssen Medal of the Astronomical Society of France. He received the Henry Norris russell Lectureship and received the Kepler Gold Medal
|
kuiper
|
|
3rd largest, and fourth most massive planet, discovered by William Herschel in 1781.
|
uranus
|
|
it has the coldest planetary atmosphere , 49 K. It has an axis of rortation tilted nearly sideways. 1986 Voyager 2 showed it as virtually featureless.
|
uranus
|
|
earliest record of it was 1690 when John Flamsteed observed it 6 times, cataloging it as 34 Tauri. Pierre Lemonnier observed it between 1750 and 1769.
|
uranus
|
|
discoverer initially thought it was a comet, and he named it George's Star. Jerome Lalande proposed to name it after the discoverer, however they settled on its current name.
|
uranus
|
|
revolved every 84 years, and the average distance is roughly 20 AU from the sun. discrepancies were found in its orbit, and John Couch Adams proposed the differences must be due to an unseen planet. Le Verrier started to research, and then Galle located the new planet.
|
uranus
|
|
because of tilt, the top gets more sunlight then the middle, but it is still hottter at the equator. It is theorized that this tilt is due to a collision with an earth-sized figure.
|
uranus
|
|
It is not understood why it has a low thermal flux. It radiates hardly any excess heat. this was thought to be because of its tilt, and the impact of a collision which depleted its temperature.
|
uranus
|
|
It was discovered to have rings second. It has 13 identified rings - recently it was found to have unknown rings, twice the distance from the planet as the previous rings. This recent discovery also spotted two small satellites, one (Mab) shares its orbit with the new ring.
|
uranus
|
|
known to have 27 satellites. Its moons are named after the works of shakespeare and Pope. Its satellites system is the least massive among the gas giants.
|
uranus
|
|
five main satellites = miranda, ariel, umbriel, titania, and oberon. Titania = 8th largest moon in the solar system. Lassell discovered Ariel and Umbriel. Kuiper found Miranda. The rest were found during the Voyager 2 fly-by.
|
uranus
|
|
inner moons include Mab and cupid. Peridta was retroactively discovered in 1999. Margaret was recently found in 2008. Two innermost moons = cordelia and Ophelia. Puck is the largest of inner moons.
|
uranus
|
|
9 irregular moons - Sycorax, and Trinculo. [also includes Prospero, Setebos, and Ferdinand.] The inclinations between 60 and 140 are devoid of moons due to the kozai instability.
|
uranus
|
|
Along with discovering a lot of planetary stuff, he composed 24 symphonies.
|
herschel
|
|
he was born in hanover. He joinedthe Hannoverian Guards. He played the cello along with the obe and the Organ.
|
herschel
|
|
he worked with his sister Caroline, in 1783 giving her a satellite. He discovered 4 moons (Oberon, Titania, Enceladus, Mimas).
|
herschel
|
|
He created an extensive catalogue of nebulae, and he discovered that oduble stars aren't optical doubles but true binary stars, proving Newton's Laws of Gravitation apply outside the solar system.
|
herschel
|
|
he found that he solar system is moving through space and found the ice caps on Mars.
|
herschel
|
|
he coined the word "asteroid" meaning star-like. he used a microscope that coral had the characteristic thin cell walls of an animal, instead of being a plant.
|
herschel
|
|
discovered heliocentric theory.
|
copernicus
|
|
His professor was Albert Brudzewski. His library was later carried off as war booty by the Swedes during the Deluge.
|
copernicus
|
|
he wrote a study on the value of money (monetae cudendae ratio) formulated Gresham's Law 70 years before Gresham. He also formulated the quantity theory of money.
|
copernicus
|
|
Bernard wapowski told someone to publsh an enclosed almanac written by him. It mentions his theories about the earth.
|
copernicus
|
|
after the death of the prince-bishop of Warmia Mauritius Ferber, he participated in the election of his successor Johannes Dantiscus.
|
copernicus
|
|
he was slightly a physician. eight years after his death, Erasmus Rehinhold would publish the Prutenic Tables, tables based on his work.
|
copernicus
|
|
He presented his major theory in his "little commentary." Georg Rheticus became his pupil, and wrote a book under him (Narratio Prima) and later published a treatise on trigonometry by him.
|
copernicus
|
|
bartolomeo Spina wanted to condemn his major work. he first recorded stellar observations with an eclipse of Aldebaran. he discussed astronomy with Clement VII.
|
copernicus
|
|
its surface is composed of basalt and iron(III) oxide.
|
mars
|
|
its history can be split up into three main epochs (Noachian - formation of the oldest extant surfaces 3.7 billion years ago. The Tharsis bulge volcano upland formed then).
Hesperian 3.5 B to 1.8 B - marked by the formation of extensive lava plains Amazonian Epoch (1.8 B to now) - Olympus Mons was formed |
mars
|
|
its soil is composed of salt perchlorate - which means it is considerably basic - measuring at 8.3.
|
mars
|
|
water was thought to have occurred during when the valles marineris formed early in Mars's history, forming massive outflow channels. A smaller but more recent outflow may have occurred when the Cerberus fossase chasm opened 5 million years ago, making frozen ice stilll visible on the Elysium Planitia.
|
mars
|
|
Johann Heinrich Madler and Wilheim Beer (along with mapping the moon) established most of its surface and determined its rotation period.
|
mars
|
|
Mariner 9 provided extensive imagery of it in 1972.
|
mars
|
|
it is thought to have an impact crater the size of europe & Asia & Australia, surpassing the South Pole - Aitken basin as the largest impact crater.
|
mars
|
|
the largest known mountain in the solar system
|
olympus mons
|
|
located in upland Tharsis, it is three times the size of Mount Everest
|
olympus mons
|
|
valles marineris (known as Agathadaemon) is its largest canyon (equivalent to the length of europe).
|
mars
|
|
lost its magnetosphere 4 B years ago. Its atmosphere is 95% CO2, 3% Nitrogen, 1.6% argon.
|
mars
|
|
missions to it include Mariner 4, Mariner 9 - the successful objects to land on it were the Soviet [planet[ 2 and 3]. Viking 1 and 2 also landed on it successfully. The most recent mission was Phoenix.
|
Mars
|
|
In 2003, NASA launched Spirit and Opportunity to go here.
|
Mars
|
|
larger and closer of two moons of mars
|
phobos
|
|
discovered by Asaph hall
|
Phobos and Deimos
|
|
most prominent crater = stickney crater, named after the discoverer's wife. the kaidun metereorite is thought to be a pieceo f this.
|
phobos
|
|
it moves around its planet faster than the planet rotates, therefore it rises in the west and moves to the east - circling twice every day.
|
phobos
|
|
because of its orbital period being so short, tidal deceleration is decreasing its orbital radius at the rate of 20 meters / century. In 11 million years it should either hit the planet, or turn into a ring. It is a Mohr-Coulomb body.
|
phobos
|
|
it is estimated it will pass the roche limit for a rubble pile when its orbital radius drops more.
|
phobos
|
|
there are speculations that it could be hollow. Iosif Samuilovich Shklovsky suggested it was a thin sheet metal. Fred Singer, science advisor to Eisenhower, supported this theory.
|
phobos
|
|
PRIME wanted to land on it. The proposed landing site is the namesake "monolith".
|
phobos
|
|
its features are named after astronomers who studied it and places from Swift's Gullivers Travelers. The only named ridge is the Kepler Dorsum.
|
phobos
|
|
smaller and outer of mars's moons
|
deimos
|
|
The two largest craters are Swift and Voltaire (3 km across)
|
deimos
|
|
unlike corresponding moon, it rises in the east and sets in the west.
|
deimos
|
|
distance within which a celestial body, held together by its own gravity, will disintegrate due to tidal forces and the body's gravitational self-attraction.
|
roche limit
|
|
depends on the rigidy of the satellite - it will maintain its shafe until tidal forces break it apart. It can also be a fluid satellite.
|
roche limit
|
|
can be derived using kepler's 3rd law + newton's law of universal gravitation. It takes into account the force of gravitation, the centrifugal force, and the self-gravitation field of the satellite.
|
roche limit
|
|
limits the mass of bodies made from electron-degenerate matter, a dense form of matter which consists of nuclei immersed in a gas of electrons.
|
chandrasekhar limit.
|
|
no rotating white dwarf can be heavier than this
|
chandrasekhar limit
|
|
happens because the energy of electrons increase because of compression since they can't operate within the same state (Pauli) - hence, pressure is exerted on the electron gas.
|
chandrasekhar limit
|
|
Lieb and yau gave a derivation of it from the schrordinger wave equation.
|
chandrasekhar limit
|
|
Ralph H. Fowler observed the relationship between density, energy and temperature of white dwarves. This Fermi gas model was used by E.C. Stoner to calculat ethe relationship - Wilheim Anderson corrected this model. Then Frenkel worked on it, but it was ignored. THen its namesake worked on it - solving the hydrostatic equation. It was also calculated by Lev Davidovich Landau.
|
chandrasekhar limit
|
|
its opposition was arthur stanley eddington, he thought that something would stop the collapse. Although Bohr, Fowler, Pauli and others agreed with his anaysis, due to Eddington, they didn't publicly support the namesake.
|
chandrasekar limit
|
|
the champagne supernova, seen by David Branch, was spinning so fast the centrifugal force exceeded this, causing it to cause a massive explosion.
|
chandrasekhar limit
|
|
group of astronomical objects listed by the name sake in his Catalogue of Nebulae and Star Clusters.
|
Messier
|
|
The original motivation was that the namesake was a comet hunter, but he was frustrated by objects that weren't comets, but resembled them. In collaboration with his assistant Pierre Mechain he put together a list.
|
messier
|
|
it first contained 103 objects ; the first edition covered 45 objects. The first addition came from camille Flammarion, who added 104. Helen Sawyer Hogg added 105-107. Owen Gingrich and Jones added a few more.
|
Messier
|
|
In the constellation Taurus - is currently expanding at about 1500 km / s
|
Crab Nebula
|
|
First observed by John Bevis in 1731 and corresponds to a bright supernova recorded by the Chinese and Arabs in 1054.
|
Crab Nebula
|
|
Named because of the Earl of Rosse who observed it at Birr Castle and referred to it by the drawing he made.
|
Crab Nebula
|
|
Iosif Shklovsky proposed that its blue region was dominated by synchroton radiation, which is given off by the curving of electrons at the speed of light.
|
crab nebula
|
|
there are two faint stars at the center. It was identified when Rudolf Minkowski found the spectrum to be extremely unusual.
|
crab nebula
|
|
it is weird that the combined mass of it + its pulsar don't add up to the progenitor star. The missing mass is thought to be between 1-5 solar masses. The main theory to solve this is a substantial portion of the mass was carried away by a stellar wind.
|
crab nebula
|
|
X-ray emissions were used to track its transity, but didn't work too well. The moon's transit helped to directly identify where it was. Every june, the sun's corona passes in transit , and variations in its radio waves can show its density. In 1296 and 2003 Saturn transited it ; Titan also had a transity - which showed Titan's atmosphere to be 880 km.
|
crab nebula
|
|
Originally thought to be orbiting the Milky way Galaxy, these are two irregular dwarf galaxies.
|
Large and Small Magellanic Clouds
|
|
Were seen by Al Sufi in 964 who, in his Book of Fixed Stars, called it the "White Ox". In Europe, it was observed by Peter Martyr and Andreas Corsali - then by Antonio Pigafetta.
|
Magellanic clouds
|
|
Roughtly 21 degrees apart and 75,000 light years away from one another. Until the discovery of the Sagittarius dwarf elliptical galaxy in 1994, they were the closest galaxies
|
magellanic clouds
|
|
The first systematic observations were carried out by Edmund Halley on the island of St. Helena. One is in the constellation Dorado, while the other is in Tucana.
|
Magellanic Clouds
|
|
The distance was estimated by Henrietta Levitt using Cepheid variable stars.
|
Magellanic Clouds
|
|
class of pulsating variable stars. The relationship between their luminosity and pulsation is precise. They are the foundation of the extragalactic distance scale.
|
cepheid variable stars.
|
|
brightest star in orion
|
rigel
|
|
sixth brightest in the sky
|
rigel
|
|
it is a blue supergiant star - between 700-900 light years away. 17 solar masses, shining with 40,000 times the luminosity of the sun. The nearest powerful star is Naos (in Puppis)
|
rigel
|
|
It lights up the witch head nebula. it is surrounded by a shell of expelled gas, perhaps by its pulsations, or stellar winds. it's not settled.
|
rigel
|
|
It has been known as a visual binary since 1831, when it was measured by F G W Struve. Its B star is separated by 2200 AU. They orbit one another every 9.8 days.
|
Rigel
|
|
Its name comes from its location at the "left foot" of Orion. It has other names like Algebar. In Chinese it is known as the "seventh of the three stars"
|
rigel
|
|
It is found below and to the ight of Mintaka, Alnilam, and Alnitak - which are in the same constellation.
|
rigel
|
|
second brightest star in Orion and the ninth brightest in the night sky
|
betelgeuse
|
|
it is a vertex of the winter triangle and center of the winter hexagon. It is a red supergiant, and one of the most luminous stars known.
|
betelgeuse
|
|
its angular diameter was first measured by michelson and Pease using the John D. Hooker interferometer atop Mount Wilson
|
betelgeuse
|
|
Theorized to have a name meaning "the hand of al-jauza" - it was at one time thought to be the "armpit of orion". In chinese astronomy it was thought to be the fourth star of the constellation.
|
betelgeuse
|
|
Its variability of brightness was first described by JohnHerschel in 1836, when published in his Outlines of Astronomy.
|
betelgeuse
|
|
it has the third largest angular diameter. It was the first to be measured with an astronomical interferometer. Direct parallax measures from space say its 495 light years away., while radio emissions give 640 light years.
|
betelgeuse
|
|
it is thought to become a supernova, outshining the moon in the night sky. Nobel Laureate Charles Townes announced that 15 years of UC Berkeley's Infrared Spatial Interferometer atop Mt. Wilson in Southern California said it has decreased 15 A% in the last 20 years.
|
betelgeuse
|
|
Brightest star in the night sky - twice as bright as canopus, the next brightest star.
|
sirius
|
|
known as the "dog star"
|
sirius
|
|
it was the first star to have its velocity measured. Sir William Huggins examined the spectrum of the star with a red shift.
|
sirius
|
|
frederich bessel deduced from changes in its motion that it had an unseen campaign. Soon, American Alvan Graham Clark found its companion, called "the Pup"
|
sirius
|
|
In 1915, Walter Sydney Adams, using a 60-inch reflecter at Mount Wilson Observatory observed its spectrum and determined it was a faint whitish star. Its diameter was first measured by Robert Hanbury Brown and RIchard Q. Twiss at Jodrell Bank.
|
sirius
|
|
these three form the winter triangle
|
procyon, betelgeuse, sirius
|
|
It was thought to maybe be a part of the Ursa Major Moving Group. But instead is thought to be a member of its namesake supercluster.
|
sirius
|
|
scatter graph of stars showing relationship between stars' absoltue magnitudes or lumonisity versus their spectral types or classifications.
|
HR diagram
|
|
the original type originally displayed the spectral type of stars on the horizontal and the absolute magnitde on the vertical axis.
|
HR diagram
|
|
most of its entries are on the main sequence. There is also a namesake gap between A5 and G0.
|
HR diagram
|
|
can be used to calculate how far a star cluster is from earth.
|
H-R Diagram
|
|
charged particles around Earth held in place by the magnetic field.
|
Van Allen radiation belt
|
|
It has a cavity, called the Chapman Ferraro Cavity, where it resides and splits into two.
|
van Allen belts
|
|
Was confirmed by Explorer I and Explorer III. Its closes approach to the surface is at the South Atlantic Anomaly.
|
Van Allen Belts
|
|
it is the product of the decay of albedo neutrons, as a result of the decay of albedo neutrons which are themselves the result of cosmic ray collisions in the upper atmosphere.
|
vann allen belts
|
|
its Ultra Deep Field Image is the msot detailed image ever.
|
hubble telescope
|
|
5 servicing missions, occurring in may 2009 - when its imaging flaw was corrected.
|
hubble telescope
|
|
the latest servicing should allow it to function until 2014, when its successor the James Webb Space telescope will be launched.
|
hubble telescope
|
|
Lyman Spitzer recommended in "Astronomical advantages of an extraterrestrial observatory" that we need a telescope in outer space. In 1965, he was put at the head of the project.
|
hubble telescope
|
|
Work on the project had been given to the Marshall Space Flight Center - which was given the responsibility for design, development, and construction.
|
hubble telescope
|
|
It is a Cassegrain reflector of Ritchley - Chretien design - it has two hyperbolic mirrors. Perkin Elmer intended to use a computer machine - but they ended up using Kodak. The Itek mirror is at the Magdalena Ridge Observatory
|
hubble telescope
|
|
Initially it held 5 scientific instruments, the Wide Field and Planetary camera, Goddard High resolution Spectrograph, High Speed Photomoter, Faint Object Camera and the Faint Object Spectrograph.
|
hubble telescope
|
|
Within a week, the images showed there was a serious problem with the optical system. the primary mirror had been in the wrong shape ; the prescribed curve of 10 nanometers. Lew Allen, director of the Jet Propulsion Laboratory was to determine how the error happened.
|
hubble telescope
|
|
COSTAR was to fix the spherical aberration (Corrective Optics Space Telescope Axial Replacement) - Riccardo Giacconi announced that he would allow amateur astronomers to use it.
|
hubble telescope
|
|
Born in Marshfield, Missouri. He worked at Mount Wilson Observatory near Pasadena California.
|
hubble
|
|
Using the Hooker Telescope, he identified Cepheid variable Stars in several spiral nebulae - including the Andromeda Nebula.
|
hubble
|
|
he discovered the redshift of galaxies, although it was understood by Keeler, Slipher, and campbell at other observatories. Comparing his measurements with Leavitt's period-luminosity relationship, he and Milton L. Humason discovered a proportionality with redshift
|
hubble
|
|
He and Humason formulated the empirical redshift distance law, termed his namesaw law. this equation is consisten with einstein's equations of general relativity for a homogenous, isotropic expanding space.
|
hubble
|
|
He used a system for classifying galaxies based on his "tuning-fork" diagram.
|
hubble
|
|
describes that various galaxies are receding from the earth is proportional to the distance from us.
|
hubble's law
|
|
the recession velocity was based on redshifts, many measured much earlier by Vesto Slipher.
|
hubble's law
|
|
Alexander Friedmann derived his Friedmann equations from Einstein's field equations showing that the universe might expand at a rate calculable by the equations - known as the scale factor. Georges Lemaitre found the same solution.
|
hubble's law
|
|
explained by the doppler effect, it's constant was published by Allan Sandage - but it would be a while before ocnsensus.
|
hubble's law
|
|
The Big Bang Interpretation of this is known as Olber's Paradox. If the universe of was infinite, static, and filled with stars, then every line of sight would be a star - and thus the sky would have the sight of a star - the solution is that light has yet to reach us.
|
olber's paradox
|
|
it is measured by the redshift of distant galaxies and determining the distances at the same time. It was debated between Gerard de Vaucouleurs - who claimed it was 100, while Sandage claimed it was 50.
|
hubble's constant.
|
|
the ACDM model of high redshift using the SUnyaev- Zel'dovich effect and optical surveys give it a value of 70
|
hubble's constant
|
|
its reciprical is proportional to time since the Big Bang - and it is required by isotropy and universal homogeneity
|
hubble's constant
|
|
Georges Lemaitre proposed it - although he called it "hypothesis of the primeval atom".
|
big bang
|
|
it relies on einstein's general relativity with simplifying assumptions, such as homogeneity and isotropy of space. The governing equations were formulated by Friedmann.
|
big bang
|
|
Fred Hoyle coined this term, during a 1949 radio broadcast. Hoyle liked the "steady state" cosmological model and wanted this to be offensive.
|
big bang
|
|
it developed from observations from many. Slipher measured the first doppler shift of a "spiral nebula." Ten years later, Friedmann derived his equations. Lemaitre then predicted the recession was due to expansion of the universe
|
big bang
|
|
Ideas to explain Hubble's observations to not support this included Milne Models, the oscillatory Universe and Fritz Zwicky's tired light hypothesis.
|
big bang
|
|
It was developed by George Gamow, who introduced its namesake nucleosynthesis) - and his associates Alpher and Herman who predicted CMB.
|
big bang
|
|
at a finite time in the past, there existed an infinite density and infinite temperature, which broke down relativity, which can't be earlier than the Planck epoch.
|
big bang
|
|
depends on two assumptions, the universality of physical laws, and the cosmological principle - which states the universe if homogenous and isotropic.
|
big bang
|
|
as the universe expanded, it cooled to where photons could no longer be created nor destroyed - but still high enough for electrons and nuclei to remain unbound. photons were continually reflected from these free electrons through thomson scattering -thus rendering the universe opaque.
|
big bang?
|
|
Arno Penzias and Robert wilson discovered this at Bell Laboratories.
|
CMB
|
|
kepler's laws
|
1) orbit is an ellipse
2)line joining planet and sun sweeps out equal areas during equal intervals 3) the square of the orbital period is directly proportional to the cube of the semi-major axis of its orbit |
|
also a statement of the conservation of angular momentum
|
kepler 2
|
|
1976 - orbiting and landing on mars
|
Viking
|
|
1979-1980 - flybys of jupiter and saturn
|
voyager I
|
|
flybys of uranus and neptune
|
voyager II
|
|
19990 - orbited venus sending back detailed radar maps of its surface
|
magellan
|
|
1995 - closeup study of jupiter and its moons
|
galileo
|
|
1997 - orbits mars sending back detailed image of surface.
|
magellan
|
|
2004 - closeup study of saturn and its moons and rings - will land a probe on titan
|
Cassini
|
|
has been observed since 240 BC - but its orbit was computed by its namesake. it last appeared in 1986 0 and will reappear in 2061.
|
halley's comet
|
|
In his Synopsis of the Astronomy of Comets - he used Newton's laws to calculate the gravitiational effects of Jupiter and Saturn on cometary orbits.
|
halley
|
|
its prediction was correct, seen on dec 25, 1758 by johann Georg Palitzch.
|
halley's comet
|
|
hypothesized spherical cloud of comets roughtly 50,000 AU from the sun. It is close to Proxima Centauri. It defines the gravitational boundary of our solar system.
|
oort cloud
|
|
It is thought to have two separate regions, a spherical outer namesake and a inner one, the Hills Cloud
|
Oort CLoud
|
|
Estonian Ernst Opik postulated thsi initially. It was suggested by its namesake.
|
oort cloud
|
|
its total mass is thought to be 5 times the earth's mass. its mass was thought to peak 800 million years ago after formation.
|
oort cloud
|
|
models by julio Angel Fernandez suggest that its scattered disk formation is the source of periodic comets. Its namesake saw "cometary fading."
|
oort cloud
|
|
Four objects are thought to belong to it so far - Sedna, Cr105, SQ372, KV42.
|
oort cloud
|
|
most luminous electromagnetic events in the universe. THey can last from illiseconds to an hour - although most last a few seconds - they usually have after - glows.
|
GRBs
|
|
First detected by Vela Satellites - initially they were thought to be collisions between comets and neutron stars. The team at Los Alamos Scientific Laboratory, led by Klebesadel, filed away the datae for investigation.
|
GRBs
|
|
BeppoSax detected one of these when its X-ray amera was pointed towards its direction. The second one placed it, through redshift, roughly 6 billion light years away. Swift was sent up to detect these.
|
GRBs
|
|
these are the systems that produce GRBs
|
progenitors
|
|
the most widely accepted model for these is the collapsar model. It is thought tto be a a massive, low metallicity, rapidly rotating star collapses into a black hole and swirls into an accretion disk. This drives jets towards the rotational axis, which are sometimes replaced with a magnetar.
|
GRBs
|
|
the closes galactic analogs of thes stars that produce these are Wolf-Rayet stars.
|
GRBs
|
|
small star composed mostly of electron-degenerate matter - they are very dense - comparable to the mass of the sun and the volume the earth.
|
white dwarves
|
|
They were recognized by Henry Norris Russell, Edward Charles Pickering and FLeming - it was coined by Willem Luyten in 1922
|
white dwarves
|
|
they are thought to be 6% of the stars in our neighborhood - while 97% of stars in our galaxy.
|
white dwarves
|
|
it is only supported by electron degeneracy pressure - the chandrasekhar limit applies to it. A carbon-oxygen one that approaches it can explode as a supernova via carbon detonation.
|
white warf
|
|
It was first discovered in the star system of 40 Eridani - the pair Eridani B/C was discvoered by Friedrich Wilhelm Herschel and then observed by Wilhelm Struve.
|
white dwarves
|
|
the majority lie between .5 to .7 solar masses. They don't consist of atoms with chemical bonds, but rather plasma of unbound nuclei and electrons.
|
white dwarves
|
|
G.P. kuiper was the first to try to classify their spectra. It was initially scaled by Edward M. Sion.
|
white dwarves
|
|
bottom left of HR diagram
|
white dwarves
|
|
their magnetic fields were predicted by P.M.S. Blackett. He thought that they should generate a magnetic field proportional to their angular momentum [blackett effect].
|
white dwarves
|
|
was first used in 1926 and coined by Swiss astrophysicist Fritz Zwicky
|
supernova
|
|
The first one was observed by Chinese astronomers in 185 AD. In the 60's - they suggested that the universe was expanded.
|
supernova
|
|
very energetic and distant galaxy with an active galactic nucleus. They were first identified as being high redshift sources of electromagnetic energy, including radio waves and visible lights.
|
quasars
|
|
they are the most luminous objects, usually tend to be 3 billion light years away. the brightest on is in Virgo.
|
quasars
|
|
they were discovered by Maarten Schmidt in 1967 and were good evidence against Fred Hoyle's Steady State cosmology.
|
quasars
|
|
have the same properties as galaxies, but are for more powerful. a minority of them show radio emission which originate as jets moving at the speed of light - appearing as a blazar.
|
quasars
|
|
the oldest ones, display a Gunn-Peterson trough and have absorption regions in front of them indicating that the intergalactic medium was neutral gas. More recents ones show no absorption regions but rather spiky areas known as Lyman - alpha forests.
|
quasars
|
|
They were first discovered with the lovell telescope as an interferometer. Hundreds of them were cataloguedi nt he Third Cambridge Catalogue. in 1962, one was hown to go through five occultations of the moon, measurements were taken by Cyril Hazard and John Bolton using hte Parkes Radio telescope and allowed maarten schmidt to identify them.
|
quasars
|
|
the term was coined by Chinese Hong-Yee Chiu.
|
quasars
|
|
it was a topic of debate in the 60's whether they are near or far - it was suggested that they were due to light escaping a deep gravitational well. however the stars int hem to form such a well would be unstable in excess of the Hayashi limit. They also show unusual spectral emissions.
|
quasars
|
|
class of galaxies with nuclei that produce spectral line emissions from highly ionized gas - named after the astronomer who identified them in 1943. They contain supermassive black holes
|
seyfert galaxies
|
|
states that the total energy radiated per unit surface area of a black body in unit time is directly proportional to the fourth power of the black body's thermodynamic temperature
|
stefan-boltzmann law
|
|
it is a certain quantitiy that if containing a sufficient amount of mass (and density) the force of gravity is so great that no known force or degeneracy pressure could stop it from collapsing it into a gravitational singularity.
|
schwarzschild radius
|
|
its namesake found an exact solution to einstein's field equations to find this quantity. it is proportional mass - for the sun it is 3 km - while the earth is 9 mm.
|
scwarzchild radius
|
|
the significance of this at r = 2M was first raised by Jacques Hadamard who asked what would happen if this occurred - einstein said it couldn't because it would destroy the universe, and called it the "Hadamard disaster"
|
singularity
|
|
an original assumption of this assumed it was an incompressible fluid. einstein argued that this could never happen. That same year, Robert Oppenheimer and Hartland Snyder considered a model of a dust lcoud and showed it could reach singularity.
|
schwarzchild radius
|
|
r = 2Gm / c2
|
schwarzchild radius
|
|
Its brightest star is Spica. A noted galaxy that is not part of it is the Sombrero Galaxy.
|
virgo
|
|
M31 - features include the brightest star - Alpheratz / Sirrah). It contains M33 - the Triangulum Galaxy.
|
andromeda
|
|
latin for cup-bearer - it contains the first planetary system found around a red dwarf. - it contains M2, M72, M73. Two well known nebula in it are The Saturn Nebula and the Helix Nebula
|
Aquarius
|
|
Latin for Ram - Its brightest star is Alpha Arietis - It includes galaxies like NGC 697, 772, ....
|
aries
|
|
latin for crab. It contains 55 Cancri - a quintuple planet system. It is the home of Praesepe (M44, big star) - also the Beehive Cluster or the Gat eof Men.
|
cancer
|
|
latin for greater dog. Contains Adhara (the Virgins), Wezen (the weight), Aludra, Furud, Muliphen. The only messier object is M41, 4 degrees below Sirius - its brightest star.
|
canis major
|
|
Latin for smaller dog - contains only two bright stars - Procyon and Gomeisa.
|
canis minor
|
|
Represents the vain queen who boasted about her beauty. Looks like a W or M - contains two stars - p Cas and V509 Cas. It contains M52 and M102. It contains Tycho's star.
|
cassiopeia
|
|
latin for twins. It is associated with castor and pollux. It contains the Eskimo Nebula. It also has the Medua nebula.
|
gemini
|
|
latin for lion. Bright stars - Regulus - Denebola. Part of its makes up the asterism known as the sickle. Wolf 359 is in it. It contains a namesake triplet and namesake ring.
|
leo
|
|
known as the "hunter' - largest constellation - it includes a prominent belt. Its stars include Betelgeuse, Rigel, Bellatrix, Mintaka, Alnilam, Alnitak, and Saiph. It contains the Trapezium and the namesake nebula. Another famous object is the Horsehead Nebula. It also contains Barnard's Loop and the Flame Nebula.
|
Orion
|
|
Named for a Greek hero, its brightest and most brilliant star is Mirfak (Algenib). It also contains Algol - which is its most famous star.
|
Perseus
|
|
latin name is plural fish. Its brightest star is Van Maanen's Star - also containing one galaxy, M34. It contains the Testudo (turtle)
|
Pisces
|
|
latin for the archer - it has an asterism known as the Teapot. One of its brightest = Rukbat. It contains the most stars with planets - 16 have them. It contains the Lagoon Nebula, the Omega nebula (Horshoe nebula), the Trifid Nebula.
|
sagittarius
|
|
latin for scorpion. Some of its bright stars include Antares. It contains the Butterfly Cluster and the Ptolemy Cluster
|
Scorpius
|
|
Latin for bull. The outline of a V or A shaped asterism of stars is a prominent member of the Hyades, the nearest distinct open star cluster. In the northeastern quadrant lie the Pleisades.
|
taurus
|
|
third brightest in Orion, 27th overall. Known as female warrior.
|
Bellatrix
|